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It is on this plan that Edison has now constructed a phonograph which delivers its reproduction to a roomful of people. Keys and pedals are provided with which to stop the apparatus either in recording or receiving, and in the latter case to hark back and repeat a word or sentence if required. This is a convenient arrangement in using the phonograph for correspondence or dictation. Each instrument, as we have seen, can be employed for receiving as well as recording; and as all are made to one pattern, a phonogram coming from any one, in any art of the world, can be reproduced in any other instrument. A little box with double walls has been introduced for transmitting the phonograms by post. A knife or cutter is attached to the instrument for the purpose of paring off an old message, and preparing a fresh surface of the wax for the reception of a new one. This can be done in advance while the new record is being made, so that no time is lost in the operation. A small voltaic battery, placed under the machine, serves to work the electric motor, and has to be replenished from time to time. A process has also been devised for making copies of the phonograms in metal by electro-deposition, so as to produce permanent records. But even the wax phonogram may be used over and over again, hundreds of times, without diminishing the fidelity of the reproduction.

The entire phonograph is shown in our figure. [The figure is omitted from this e-text] It consists of a box, B, containing the silent electro-motor which drives the machine, and supporting the works for printing and reproducing the sounds. Apart from the motive power, which might, as in the graphophone, be supplied by foot, the apparatus is purely mechanical, the parts acting with smoothness and precision.

These are, chiefly, the barrel or cylinder, C, on which the hollow wax is placed; the spindle, S, which revolves the cylinder and wax; and the two tympana, T, T', which receive the sounds and impress them on the soft surface of the wax. A governor, G, regulates the movement of the spindle; and there are other ingenious devices for starting and stopping the apparatus. The tympanum T is that which is used for recording the sounds, and M is a mouthpiece, which is fixed to it for speaking purposes. The other tympanum, T', reproduces the sounds; and E E is a branched ear-piece, conveying them to the two ears of the listener. The separate wax tube, P, is a phonogram with the spiral trace of the sounds already printed on its surface, and ready for posting.

The box below the table contains the voltaic battery which actuates the electro-motor. A machine which aims at recording and reproducing actual speech or music is, of course, capable of infinite refinement, and Edison is still at work improving the instrument, but even now it is substantially perfected.

Phonographs have arrived in London, and through the kindness of Mr.

Edison and his English representative, Colonel G. E. Gouraud, we have had an opportunity of testing one. A number of phonograms, taken in Edison's laboratory, were sent over with the instruments, and several of them were caused to deliver in our hearing the sounds which were'sealed in crystal silence there.'

The first was a piece which had been played on the piano, quick time, and the fidelity and loudness with which it was delivered by the hearing tube was fairly astonishing, especially when one considered the frail and hair-like trace upon the wax which had excited it. There seemed to be something magical in the effect, which issued, as it were, from the machine itself. Then followed a cornet solo, concert piece of cornet, violin, and piano, and a very beautiful duet of cornet and piano. The tones and cadences were admirably rendered, and the ear could also faintly distinguish the noises of the laboratory. Speaking was represented by a phonogram containing a dialogue between Mr. Edison and Colonel Gouraud which had been imprinted some three weeks before in America. With this we could hear the inventor addressing his old friend, and telling him to correspond entirely with the phonograph.

Colonel Gouraud answers that he will be delighted to do so, and be spared the trouble of writing; while Edison rejoins that he also will be glad to escape the pains of reading the gallant colonel's letters.

The sally is greeted with a laugh, which is also faithfully rendered.

One day a workman in Edison's laboratory caught up a crying child and held it over the phonograph. Here is the phonogram it made, and here in England we can listen to its wailing, for the phonograph reproduces every kind of sound, high or low, whistling, coughing, sneezing, or groaning. It gives the accent, the expression, and the modulation, so that one has to be careful how one speaks, and probably its use will help us to improve our utterance.

By speaking into the phonograph and reproducing the words, we are enabled for the first time to hear ourselves speak as others hear us;for the vibrations of the head are understood to mask the voice a little to our own ears. Moreover, by altering the speed of the barrel the voice can be altered, music can be executed in slow or quick time, however it is played, inaudible notes can be raised or lowered, as the case may be, to audibility. The phonograph will register notes as low as ten vibrations a second, whereas it is well known the lowest note audible to the human ear is sixteen vibrations a second. The instrument is equally capable of service and entertainment. It can be used as a stenograph, or shorthand-writer. A business man, for instance, can dictate his letters or instructions into it, and they can be copied out by his secretary. Callers can leave a verbal message in the phonograph instead of a note. An editor or journalist can dictate articles, which may be written out or composed by the printer, word by word, as they are spoken by the reproducer in his ears.